drm/vmwgfx: Return -ENOENT when a framebuffer can't be found

Let's be a bit more consistent with our error values.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

drivers/gpu/drm/vmwgfx/vmwgfx_ioctl.c

@@ -168,7 +168,7 @@ int vmw_present_ioctl(struct drm_device *dev, void *data,
 	fb = drm_framebuffer_lookup(dev, arg->fb_id);
 	if (!fb) {
 		DRM_ERROR("Invalid framebuffer id.\n");
-		ret = -EINVAL;
+		ret = -ENOENT;
 		goto out_no_fb;
 	}
 	vfb = vmw_framebuffer_to_vfb(fb);
@@ -252,7 +252,7 @@ int vmw_present_readback_ioctl(struct drm_device *dev, void *data,
 	fb = drm_framebuffer_lookup(dev, arg->fb_id);
 	if (!fb) {
 		DRM_ERROR("Invalid framebuffer id.\n");
-		ret = -EINVAL;
+		ret = -ENOENT;
 		goto out_no_fb;
 	}